The present invention generally relates to computer assisted medical navigation systems, and more specifically, but not exclusively, concerns a trackable medical instrument that is rotationally lockable.
Computer assisted medical navigation systems aid in guiding medical instruments within a patient during surgery. With such systems, images of the body of the patient are taken with an imaging device, such as a CAT scanner (Computerized Axial Tomography scanner). The medical instrument has a tool that is attached to a guide member, and a tracking device is attached to the medical instrument so that the tool can be tracked by the system. The surgeon positions the instrument by viewing on a display the relative position of the tool within the patient in order to avoid damaging organs. Generally, the longitudinal position of the tool is fixed so that the exact position of the tool can be determined. With some medical instruments that rotate during use, such as drills, a surgeon using the system cannot determine the exact orientation of the instrument during surgery. Serious injury to the patient can occur if the tool is unexpectedly rotated or oriented at the wrong position during surgery. Therefore, there is a need in the art for a medical navigation system that is simple to use and that can precisely locate the orientation of a rotatable surgical instrument.
One form of the present invention is directed to a unique trackable medical instrument. The medical instrument includes a guide member and emitter coupled to the guide member. The emitter array is used to track the position of the guide member. A drive shaft is rotatably coupled to the guide member, and a locking mechanism is provided along the drive shaft. The locking mechanism has an unlocked position in which the drive shaft rotates relative to the guide member, and the locking mechanism has a locked position in which the drive shaft is rotationally stationary relative to the guide member.